package org.blog.encryption;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
/**
 * 
 * @author Maciej Koch
 *
 */
public class MD5 {
	
	/**
	 * <p>
	 * Koduje tekst na 32 bity, zgodnie z algorytmem MD5
	 * </p>
	 * @param text to encode
	 * @return encoded text
	 * @throws NoSuchAlgorithmException
	 */
    public static String encrypt(String text) throws NoSuchAlgorithmException{ 
        MessageDigest md;
        md = MessageDigest.getInstance("MD5");
        byte[] md5hash = new byte[32];
        try {
			md.update(text.getBytes("iso-8859-1"), 0, text.length());
		} catch (UnsupportedEncodingException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
        md5hash = md.digest();
        return convertToHex(md5hash);
    }
	
	private static String convertToHex(byte[] data) { 
        StringBuffer buf = new StringBuffer();
        for (int i = 0; i < data.length; i++) { 
            int halfbyte = (data[i] >>> 4) & 0x0F;
            int two_halfs = 0;
            do { 
                if ((0 <= halfbyte) && (halfbyte <= 9)) 
                    buf.append((char) ('0' + halfbyte));
                else 
                    buf.append((char) ('a' + (halfbyte - 10)));
                halfbyte = data[i] & 0x0F;
            } while(two_halfs++ < 1);
        } 
        return buf.toString();
    } 
  
}
